Created attachment 359564 [details] Simple reproducer. Description of problem: Since bug 206806 was fixed in 2.6.18-98.el5 the ia64 kernel implements the pselect() and ppoll() syscalls. glibc is still not using them as of RHEL-5.3 and instead emulates it with the racy equivalent. Version-Release number of selected component (if applicable): glibc-2.5-34 How reproducible: Always. Steps to Reproduce: 1. Compile and run test program attached. Actual results: Pending signals are caught at sigprocmask() time and then select() may block forever, in the racy pselect() "equivalent". Expected results: Use the actual pselect() syscall that will then return pending signals and not block forever. Additional info: x86_64 and ia64 straces of the test program will be attached.
Created attachment 359565 [details] Correct x86_64 pselect() call.
Created attachment 359566 [details] Incorrect ia64 pselect() emulated by glibc.
This is a bug in kernel-headers, it needs to define the syscalls. glibc then just needs to be rebuilt against the fixed kernel-headers and it will magically pick up the syscalls.
Created attachment 361518 [details] RHEL5 fix for this issue Patch that resolves this issue. Tested by doing 1. compile reproducer with existing glibc. Test fails. 2. apply patch to tree, and install kernel-headers. 3. rebuild glibc rpms 4. reinstall glibc rpms 5. compile reproducer. Test succeeds: [root@altix4 tmp]# ./doit Calling pselect. Test succeeded.
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
in kernel-2.6.18-168.el5 You can download this test kernel from http://people.redhat.com/dzickus/el5 Please do NOT transition this bugzilla state to VERIFIED until our QE team has sent specific instructions indicating when to do so. However feel free to provide a comment indicating that this fix has been verified.
~~ Attention Customers and Partners - RHEL 5.5 Beta is now available on RHN ~~ RHEL 5.5 Beta has been released! There should be a fix present in this release that addresses your request. Please test and report back results here, by March 3rd 2010 (2010-03-03) or sooner. Upon successful verification of this request, post your results and update the Verified field in Bugzilla with the appropriate value. If you encounter any issues while testing, please describe them and set this bug into NEED_INFO. If you encounter new defects or have additional patch(es) to request for inclusion, please clone this bug per each request and escalate through your support representative.
Clearing stale NEEDINFO request.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2010-0178.html